The Department of Environment and Natural Resources closes public comment tomorrow on the wastewater disposal pipeline that Agropur wants to build from its expanding Lake Norden cheese factory to the Big Sioux River.
Among the public comments will be a letter from the East Dakota Water Development District expressing its Board of Directors’ unanimous concern about nitrates in Agropur’s wastewater. The EDWDD minutes from its April 19 meeting indicate that chairman Martin Jarrett raised concerns that the draft DENR surface water discharge permit sets no limit on nitrate levels in the two million gallons of water a day that Agropur will dump into the Big Sioux. EDWDD manager Jay Gilbertson compared the proposed wastewater nitrates with existing levels:
According to information provided by Agropur, included in the SD DENR Statement of Basis, the effluent from the facility will contain nitrate at concentrations of 37 mg/L.
The Manager noted that during the past several years, the District has been monitoring nitrate concentrations along the length of the Big Sioux River. In general, nitrate levels have been quite low (less than 2.0 mg/L), except immediately below facilities with SWD permits, such as Watertown and Sioux Falls waste water treatment facilities. The elevated nitrate concentrations have been found to persist downstream for many miles, particularly during periods of lower overall stream flow. He noted that one of the District monitoring sites is approximately ½ mile downstream of the proposed discharge location [East Dakota Water Development District, draft meeting minutes, 2018.04.19].
High nitrates in water can corrupt your hemoglobin and deprive the body of oxygen. Infants are most susceptible to this problem—the condition is called methemoglobinemia, or “blue baby syndrome”. The federal government has thus set standards under the Clean Water Act of 1974:
The federal standard for nitrate in drinking water is 10 milligrams per liter (10 mg/l) nitrate-N, or 45 mg/l nitrate-NO3. when the oxygen is measured as well as the nitrogen. Unless otherwise specified, nitrate levels usually refer only to the amount of nitrogen present, and the usual standard, therefore, is 10 mg/l.
…Because potential health risks are often unknown or hard to predict, many drinking water standards are set at some fraction of the level of “no-observed adverse-health effects.” In general, the greater the uncertainty about potential health effects, the greater the margin of safety built into the standard.
In the case of nitrate, there may not be a large safety factor. A 1977 report by the National Academy of Science concluded that “available evidence on the occurrence of methemoglobinemia in infants tends to confirm a value near 10 mg/l nitrate as nitrogen as a maximum no-observed adverse-health-effect level, but there is little margin of safety in this value” [Margaret McCasland et al., “Nitrate: Health Effects in Drinking Water,” Cornell University Cooperative Extension: Pesticide Safety Education Program, retrieved 2018.05.10].
The nitrate measurements in question are for nitrate-NO3; thus, Agropur’s projected peak nitrate dumping of 37 mg/L would be 18% below the Clean Water Act maximum at the tailpipe, and that high-nitrate water will be diluted into a lot of river water. Still, those higher nitrates will take up some of the safety margin in the river and could affect lots of drinking water downstream:
Chairman Jarrett expressed concern on behalf of the numerous public water supplies (PWSs) that are located downstream of the point of discharge. Most PWSs utilize the shallow Big Sioux aquifer, which is hydraulically connected to the Big Sioux River. The worry is that if unconstrained discharge of nitrates continues into the river, there will be significant adverse impacts on the PWSs and the tens of thousands of customers [EDWDD, 2018.04.19].
The Agropur wastewater pipeline won’t kill the Big Sioux or its users, but it will add to the nitrate pollution and eat up some of the watershed’s absorptive budget. Another big source of nitrate pollution, swine feedlots, are on the increase—two of three new swine CAFOs under consideration by DENR right now are downstream in the Big Sioux watershed—so every new source of pollutants moves us closer to the river’s maximum safe capacity for nitrates.
By the way, the Clean Water Act is among the environmental protections that Trump EPA chief Scott Pruitt is dismantling (perhaps so he can shift more funds to his outsized and paranoid security budget). And as attorney general back in Oklahoma, Pruitt did nothing to enforce clean water standards against swine CAFOs that caused excessive nitrate pollution.
Been my experience that most rivers show a serious depletion of water in the dog days of summer, meaning concentrations of nitrates will not be diluted by copious amounts of river water for a number of months each year.
Will Agropur beg their confined bovines to pee less nitrates when river levels abscond?
The river that runs through my little neighborhood (South Platte), downstream from our aerospace, rocket factory has a level of (6 mg/l) nitrate-N. Recreational kayaking happens but isn’t recommended for good health.
I love cheese more than sweets. As a chef, exotic cheese is my passion. I worked as a teen in a cheese factory in Big Stone but they aren’t building any more Sioux Rivers. Using the river to make money should be mitigated and soon stopped completely. C’mon. Find some value in what God gave you and nurture it like it’s your child.
They are below the limits set by law. What is the issue Cory?
Wouldn’t surprise me in the least bit if the Troll and his brethren in Drumpf’s rogue cabinet decided that nitrate levels can be safely raised astronomically because controlling them is too expensive.
Kinda the way dumbass dubya allowed a large increase in mercury levels. https://www.ewg.org/news/testimony-official-correspondence/new-government-fish-tests-raise-mercury-concerns#.WvRqwLiU4cU
Jason, the drinking water standard is usually set low enough to be protective of public health, with an adequate cushion. Thus, if the standard is exceeded by minimal amounts from time to time, the water wouldn’t affect your health. Studies indicate that the nitrate standard may not have an adequate enough cushion to be expected to protect sensitive individuals, mainly infants and toddlers.
The focus on specific numbers often gets in the way of taking action when there is an upward trend in a specific water quality parameter that hasn’t reached the point of violating a standard. In the case of Brohm’s Gilt Edge Mine, the Technical Information Project followed the water quality trends at various wells at the mine over time. The trends showed continual upward trends in certain parameters, and we suggested DENR look into whether the heap leach pads were leaking. They sort of blew this off because they were focused on the number and the standard, rather than the trend. It ended up we were right. The heap leach pads had failed, and Brohm had to reconstruct the pads, but not before standards were broken.
In the case of the Agopur discharge there is question of the nitrate loading, which is different from the particular parameter concentration at discharge, and the transfer to groundwater, affects on fish and wildlife, etc. That amount of loading is going to affect the environment for a stretch of the river.